Sounds very promising, but if you want to run 10W leds and about 4-8 of them.. this would not work i guess?

Driving 10 watt leds shouldn't be a problem. All you'd have to consider the Vf of you particular 10 watt led. Most of them, that I've run across, have a Vf of around 12 volts, so you should be able to run 2 of them in series on each chip. Each CAT4101 is rated to handle up to 1000ma at 25 volts maximum ( 25 watts total), so driving (2) 10 watt emitters at 800ma would yield approximately 20 watts per string. That scenario would let you drive (12) 10 watt emitters from this driver design. I have personally used 2 CAT4101's wired in parallel to drive BridgeLux 50 watt emitters, so this driver design could be configured to drive 3 of those same 50 watt emitters.